Protective garments include woven and non-woven fabrics for disposable use. The garments are generally formed from polymeric or laminated materials which are intrinsically dust or liquid penetration resistant and in some cases resistant to chemical vapor penetration. The fabrics are generally spunbonded, meltspun or related non-woven thermoplastic material. The vapor or gas-tight suits must meet the permeation criterion of ASTM D-739-85 and the liquid barrier suits must meet the penetration criterion of ASTM F903-84. For example, the suits are evaluated by exposure to a liquid permeation test medium, such as a mixture comprising 4 weight percent polychlorinated biphenyl, 6 weight percent trichlorobenzene, and 90 weight percent mineral spirits, or other multicomponent or single component test medium which is applied to the seam area of a garment sample, and the breakthrough time to penetration is measured.
Also, the non-woven fibrous fabrics must stop the penetration of dust from reaching the clothing or skin of the person wearing the garment.
U.S. Pat. No. 4,272,851 to Goldstein, which is herewith incorporated by reference, discloses a protective garment for use in hazardous environments, the body of the garment being formed of a non-woven spun bonded olefin having a polyethylene film laminated to one side thereof. This garment utilizes bonded seams which are ultrasonically welded. A sewn binding is sewn externally of the bonded seam so that the welded seam is located between the stitching and the interior of the garment. The ultrasonic bonding requires close control and the bonding does not produce seams of satisfactory strength.
U.S. Pat. No. 5,082,721 to Smith et al, which is herewith incorporated by reference, discloses fabric for use in manufacturing protective garments that can be used in the present invention.
Sewn seams cause needle holes which provide penetration by dust or vapors through the holes or the seams themselves.
Bonded seams formed by hot melt adhesive joining methods are known in various applications, but have the disadvantage that they typically weaken the seam's supporting fabric by thermal degradation thereof during seam-forming operation so that the mechanical properties of the supporting fabric, e.g., its tensile strength, are detrimentally reduced.